This invention relates generally to devices for controlling a cursor on a display screen, also known as pointing devices. This invention relates more particularly to a pushbutton optical pointing device.
The use of a hand operated pointing device for use with a computer and its display has become almost universal. By far the most popular of the various devices is the conventional (mechanical) mouse, used in conjunction with a cooperating mouse pad. Centrally located within the bottom surface of the mouse is a hole through which a portion of the underside of a rubber-surfaced steel ball extends. The mouse pad is typically a closed cell foam rubber pad covered with a suitable fabric. Low friction pads on the bottom surface of the mouse slide easily over the fabric, but the rubber ball does not skid. Rather, the rubber ball rolls over the fabric as the mouse is moved. Interior to the mouse are rollers, or wheels, that contact the ball at its equator and convert its rotation into electrical signals representing orthogonal components of mouse motion. These electrical signals are coupled to a computer, where software responds to the signals to change by a xcex94X and a xcex94Y the displayed position of a pointer (cursor) in accordance with movement of the mouse. The user moves the mouse as necessary to get the displayed pointer to a desired location or position. Once the pointer on the screen points at an object or location of interest, a button on the mouse is activated with the fingers of the hand holding the mouse. The activation serves as an instruction to take some action, the nature of which is defined by software in the computer.
In addition to mechanical types of pointing devices like a conventional mouse, optical pointing devices have also been developed, such as those described in the incorporated patents and patent application. In one form of an optical pointing device, rather than using a moving mechanical element like a ball in a conventional mouse, relative movement between an imaging surface, such as a finger or a desktop, and photo detectors within the optical pointing device, is optically sensed and converted into movement information.
For portable electronic devices, such as cellular telephones, personal digital assistants (PDAs), digital cameras, portable game devices, pagers, portable music players (e.g., MP3 players), and other devices, it may be undesirable to use an external pointing device, such as a mechanical mouse or an optical mouse, coupled to the device. It is often inconvenient to carry around the additional equipment. And with a mechanical pointing device like a mouse, it may be difficult to find a suitable surface on which to operate the mouse.
Some portable electronic devices include built-in screen pointing devices. For example, some cellular telephones include arrow keys that allow a highlight bar to be moved around on a display screen to highlight menu items, such as names or telephone numbers. Once a menu item has been highlighted, the menu item is typically selected by pressing another key on the cellular telephone. Using multiple keys to highlight and select menu items is inefficient and time consuming, particularly for users who are more familiar with operating other types of screen pointing devices, such as a mouse or trackball, or an optical pointing device.
Some portable electronic devices also include indicators, such as blinking lights or audible indicators, to provide some type of notification to a user, such as a notification that the user has received an email message or voicemail message. For example, some telephones include a blinking light to notify the user that the user has received a voicemail message. Such indicators are typically provided by a standalone LED on the device, on a display screen of the device, or by an audio subsystem, and are not incorporated into a screen pointing device.
It would be desirable to provide an optical screen pointing device for use in a portable electronic device that combines screen pointer motion control, selection capabilities, and indication functions into a single compact device.
One form of the present invention provides an apparatus for controlling the position of a screen pointer for an electronic device having a display screen. The apparatus includes a pushbutton for selecting an item displayed on the display screen. The pushbutton includes an imaging surface against which a portion of the tip of a human digit may be placed. A light source illuminates that portion of the tip of the digit that is placed against the imaging surface, thereby generating reflected images. The apparatus includes a motion transducer. A lens receives the reflected images and directs the reflected images onto the motion transducer. The motion transducer generates digital representations of the reflected images. The motion transducer generates a first set of movement data based on the digital representations of the reflected images. The first set of movement data is indicative of motion of the tip of the digit across the imaging surface.
Another form of the present invention provides a method of controlling the position of a screen pointer for an electronic device having a display screen. A pushbutton for selecting an item displayed on the display screen is provided. A portion of an appendage of the human hand is placed against the pushbutton. A portion of the appendage that is against the pushbutton is illuminated. Images reflected from the portion of the appendage are focused onto an array of photo detectors. Output values of the photo detectors are digitized, thereby generating digital representations of the reflected images. At least one version of a first one of the digital representations is correlated with at least one version of a second one of the digital representations to generate a first set of motion data indicative of motion in orthogonal axes across the pushbutton by the appendage. The position of the screen pointer is adjusted in accordance with the first set of motion data.
Another form of the present invention provides a portable electronic device including a display screen for displaying a plurality of selectable items and a pointer movable by a user to identify particular ones of the selectable items. A motion sensing pushbutton senses movement across the pushbutton by an imaging surface. The pushbutton is configured to generate a first set of movement data indicating a first movement of the imaging surface across the pushbutton, and is configured to generate a selection signal when pushed by a user. A controller is configured to move the pointer based on the first set of movement data to identify a first selectable item. The controller is configured to select the first menu item based on the selection signal generated by the pushbutton.